This study presents a flexible hemline-shaped microfiber platform for directional liquid transport. The microfibers, fabricated using microfluidics, have periodic parallel microcavities along their length with sharp edges and wedge corners that enable unilateral pinning and capillary rise of liquids. These fibers can achieve directional liquid transport along hydrophilic substrates using a single fiber, or along hydrophobic substrates or even without a substrate using a pair of fibers. The platform demonstrates versatility in transporting various liquids along arbitrary three-dimensional paths and is applied for droplet manipulation, long-distance liquid transport, and water-oil separation. The microfibers are generated by combining piezoelectric-induced vibration in a microfluidic channel with rapid photopolymerization. The fibers have a hemline-shaped cross-section with periodic microcavities and wedge corners, enabling unidirectional liquid transport. The transport behavior is influenced by parameters such as the piezoelectric frequency, voltage, and flow rates. The fibers can transport liquids on hydrophilic and hydrophobic substrates, and can even function without a substrate. The platform enables flexible and substrate-free liquid transport, and has potential applications in open microfluidics, water extraction, and energy and environmental engineering. The study highlights the advantages of the hemline-shaped microfibers, including their ability to transport liquids of different types and along various paths, and their potential for practical applications. The fibers can be tailored by adjusting operational parameters, and their flexibility allows for transport on curved surfaces. The platform demonstrates the ability to extract water from oil and to transport water along complex paths, including spiral and dangling paths. The results show that the hemline-shaped microfibers can achieve unidirectional liquid transport on a wide range of substrates and in various environments, making them a promising solution for directional liquid transport in diverse scenarios.This study presents a flexible hemline-shaped microfiber platform for directional liquid transport. The microfibers, fabricated using microfluidics, have periodic parallel microcavities along their length with sharp edges and wedge corners that enable unilateral pinning and capillary rise of liquids. These fibers can achieve directional liquid transport along hydrophilic substrates using a single fiber, or along hydrophobic substrates or even without a substrate using a pair of fibers. The platform demonstrates versatility in transporting various liquids along arbitrary three-dimensional paths and is applied for droplet manipulation, long-distance liquid transport, and water-oil separation. The microfibers are generated by combining piezoelectric-induced vibration in a microfluidic channel with rapid photopolymerization. The fibers have a hemline-shaped cross-section with periodic microcavities and wedge corners, enabling unidirectional liquid transport. The transport behavior is influenced by parameters such as the piezoelectric frequency, voltage, and flow rates. The fibers can transport liquids on hydrophilic and hydrophobic substrates, and can even function without a substrate. The platform enables flexible and substrate-free liquid transport, and has potential applications in open microfluidics, water extraction, and energy and environmental engineering. The study highlights the advantages of the hemline-shaped microfibers, including their ability to transport liquids of different types and along various paths, and their potential for practical applications. The fibers can be tailored by adjusting operational parameters, and their flexibility allows for transport on curved surfaces. The platform demonstrates the ability to extract water from oil and to transport water along complex paths, including spiral and dangling paths. The results show that the hemline-shaped microfibers can achieve unidirectional liquid transport on a wide range of substrates and in various environments, making them a promising solution for directional liquid transport in diverse scenarios.